Marimonadida
| Marimonadida | |
|---|---|
 | |
| Phase contrast micrograph of Auranticordis quadriverberis showing flagella emerging from the groove (white arrow) | |
Scientific classification  | |
| Domain: | Eukaryota |
| Clade: | Sar |
| Clade: | Rhizaria |
| Phylum: | Cercozoa |
| Subphylum: | Filosa |
| Class: | Imbricatea |
| Order: | Marimonadida Cavalier-Smith & Bass in Howe et al. 2011[1] |
| Families | |
Marimonadida (from Latin mare 'sea' and Greek monas 'unit') is an order of marine single-celled flagellates belonging to the phylum Cercozoa.
Etymology
[edit]The name Marimonadida derives from Latin mare 'sea' and Greek monas 'unit', in reference to the exclusively marine zooflagellates that compose this order.[1]
Description
[edit]Marimonadida is an order of flagellates, single-celled eukaryotes with at least two flagella used for movement. Cells of Marimonadida may move by swimming, as in the parasitoid Pseudopirsonia, or gliding, as in the free-living genera Auranticordis,[1] Abollifer[2] and Cyranomonas. They have only been detected in marine environments.[3]
Although the molecular affinities between marimonads are well supported, to date there is no known morphological trait that unites them, perhaps due to insufficient knowledge on their ultrastructure. Their cytoskeletal arrangement shows some affinities with that of the related thaumatomonads and spongomonads, and are possibly a synapomorphy of their common ancestor.[2]
Taxonomy
[edit]The order Marimonadida was first described in 2011 by Thomas Cavalier-Smith and David Bass to accommodate various 'naked' flagellates (that is, without any scales or theca covering their cells) that form a clade related to cercozoan scaled flagellates and testate amoebae, namely thaumatomonads and euglyphids. Initially, it contained three genera: Pseudopirsonia, Auranticordis, and the amoeboflagellate genus Rhabdamoeba. The enigmatic Rhabdamoeba, which at the time was not genetically sequenced, was included here due to the two adhering posterior gliding flagella of its flagellated stage, similar to the four gliding flagella of Auranticordis.[1] Eventually, Rhabdamoeba was sequenced and resolved as a member of Chlorarachnea, a different group of cercozoans that include photosynthetic amoeboflagellates.[4]
In 2014, a species of Abollifer, a genus of previously unknown taxonomic position, was placed in the order Marimonadida based on morphological and molecular analyses.[2] In 2016, phylogenetic analyses placed another previously unclassified genus, Cyranomonas, as a close relative to marimonads,[3] and was later added to the order.[5] In 2018, each genera were assigned to separate families (Abolliferidae, Auranticordidae, Cyranomonadidae and Pseudopirsoniidae). The unsequenced genus Cowlomonas was proposed (not described) by Cavalier-Smith et al. as a member of Abolliferidae, as well as the genus Heterochromonas,[5] which is often regarded as a possible genus of colorless golden alga.[6][7]
Since its description, Marimonadida has been assigned to the class Imbricatea, which contains the euglyphid testate amoebae and the thaumatomonads, as well as an array of clades of non-scaled flagellates, such as spongomonads.[1][5] However, Cercozoa-wide phylogenomic analyses have not recovered a monophyletic Imbricatea, and instead position marimonads, euglyphids and thaumatomonads intermixed with other cercozoan groups, such as cercomonads and thecofiloseans. These results are summarized in the cladogram below (uncharacterized sequences omitted):[8]
| Filosa |
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||
References
[edit]- 1 2 3 4 5 Howe, Alexis T.; Bass, David; Scoble, Josephine M.; Lewis, Rhodri; Vickerman, Keith; et al. (2011). "Novel Cultured Protists Identify Deep-branching Environmental DNA Clades of Cercozoa: New Genera Tremula, Micrometopion, Minimassisteria, Nudifila, Peregrinia". Protist. 162 (2): 332–372. doi:10.1016/j.protis.2010.10.002.
- 1 2 3 Shiratori, Takashi; Yokoyama, Akiko; Ishida, Ken-Ichiro (2014). "Phylogeny, Ultrastructure, and Flagellar Apparatus of a New Marimonad Flagellate Abollifer globosa sp. nov. (Imbricatea, Cercozoa)". Protist. 165 (6): 808–824. doi:10.1016/j.protis.2014.10.003.
- 1 2 Lee, Won Je; Park, Jong Soo (2016). "Placement of the unclassified Cyranomonas australis Lee 2002 within a novel clade of Cercozoa". European Journal of Protistology. 56: 60–66. doi:10.1016/j.ejop.2016.06.004.
- ↑ Shiratori, Takashi; Ishida, Ken‐ichiro (2024). "Rhabdamoeba marina is a heterotrophic relative of chlorarachnid algae". Journal of Eukaryotic Microbiology. 71 (2) e13010. doi:10.1111/jeu.13010.
- 1 2 3 Cavalier-Smith, Thomas; E. Chao, Ema; Lewis, Rhodri (27 April 2018). "Multigene phylogeny and cell evolution of chromist infrakingdom Rhizaria: contrasting cell organisation of sister phyla Cercozoa and Retaria". Protoplasma. 255 (5): 1517–1574. doi:10.1007/s00709-018-1241-1. PMC 6133090. PMID 29666938.
- ↑ Grossmann, Lars; Bock, Christina; Schweikert, Michael; Boenigk, Jens (2016). "Small but Manifold – Hidden Diversity in "Spumella‐like Flagellates"". Journal of Eukaryotic Microbiology. 63 (4): 419–439. doi:10.1111/jeu.12287. PMC 5066751. PMID 26662881.
- ↑ Jeong, Minseok; Kim, Jong Im; Nam, Seung Won; Shin, Woongghi (26 October 2021). "Molecular Phylogeny and Taxonomy of the Genus Spumella (Chrysophyceae) Based on Morphological and Molecular Evidence". Frontiers in Plant Science. 12 758067. doi:10.3389/fpls.2021.758067. PMC 8577464. PMID 34764972.
- ↑ Lax, Gordon; Cooney, Elizabeth C.; Zlatogursky, Vasily; Mtawali, Mahara; Okamoto, Noriko; et al. (30 January 2026). "Phylogenomic tree of Cercozoa based on single-cell transcriptomes from 100 uncultured cells". BMC Biology. 24 (1) 55. doi:10.1186/s12915-026-02536-4. ISSN 1741-7007. PMC 12930898. PMID 41618358.